The present invention relates to a coupling for rigidly connecting two coaxial rotatable machine parts, suitable for the transmission of torque from one to the other and, more particularly, to such a coupling which includes a layer of granular material between the contact surfaces of two halves of the coupling.
The known couplings for rotary machine parts generally comprise two flanges having planar faces which flanges abut one another and which planar faces are arranged vertically with respect to the axis of rotation. The flanges and planar faces are fastened to each other by screws or other connecting elements and the torque is transferred thereby exclusively by frictional resistance and the tensile stress of the connecting elements.
The transference of the torque is limited by the space requirement for the flanges and the axial tension force of the abutting connecting elements. In the specific coupling shown in U.S. Pat. No. 4,242,889 which issued to Mueller, et al on Jan. 6, 1981, the front faces of the flanges are provided with conical grooves or ribs, respectively. As a result, an increased frictional resistance is generated under the tension force of the connecting screws which permits the transfer of the major circumferential forces and torque. However, in such structures, the flanges must be formed and made by a precise and therefore expensive process. Soiling of or damage to the ribs or grooves creates the danger of error in the assembly or an inexact centering of the two flanges.
It is also known to design friction surfaces of various materials which contact each other. For instance, coatings of sintered metal, plastic material, or other composite materials have been used for multiple disk clutches, or brake linings. The object is always to increase the friction between the contact surfaces, especially when the latter would tend to slide against each other during operation.
In couplings having frontal faces, which are in a relatively rest position with respect to each other, substantially higher surface loads tend to be exerted. Known friction linings cannot last long when used in such couplings. Frequently, flange connections, such as flange connections for shafts carrying pressurized fluid mediums, must in addition, be leakproof. The ability of the flange connection to be leak proof creates a greater difficulty, such as when manufacturing, particularly with composite and separately fastened friction linings.
The invention is predicated on the task of creating a flange connection between two machine parts for the effective transfer of torque.
It is a particular object to provide a coupling connection which is simple in structure and has a smaller flange diameter.
These objects together with other objects and advantages, are set forth and will be apparent from the following disclosure of the present invention.